42.h4?! h5 43.Kf3 g6 44.Rd2 Ke6 45.Rb2 Kf6 46.Rb6+ Kf7 47.Rd6 Ra2 48.Rd4 Kf6 49.Rb4 Ke6 50.e4 fxe4+ 51.Rxe4+ Kf5 52.Rb4 Ra3+ 53.Kg2 Ra5 54.Rf4+ Ke6 55.Rf3 Ra4 56.Rb3 Kf5 57.Rb5+ Kf6 58.Rd5 Ra3 59.Kf1 Ra2 60.Ke1 Ke6 61.Rd2 Ra4 62.Ke2 Ra5 63.Rd3 Kf5 64.Rf3+ Ke5 65.Rf8 Ra2+ 66.Kf3 Ra3+ 67.Kg2 Ke6 68.Rf3 Ra2 69.Rc3 Ra5 70.Kf3 Kf5 71.Ke2 Ra2+ 72.Ke3 Ra5 73.f3 Ke5 74.g4 hxg4 75.fxg4 Ra4 76.Kf3 Kf6 77.Rc6+ Kg7 78.Re6 Kf7 79.Re4 Ra5 80.Kf4 Kf6 81.Rb4 Ra6 82.g5+ Ke6 83.Kg4 Ra1 84.Rf4 Ke7 85.Rf6 Ra4+ 86.Rf4 Ra1 87.Rb4 Kf7 88.Kf4 Ra5 89.Ke4 Kg7 90.Rb7+ Kg8 91.Rd7 Ra4+ 92.Ke5 Rxh4 93.Kf6 Ra4 94.Kxg6 Ra6+ 95.Kh5 Rb6 96.Re7 Ra6 97.Kg4 Ra5 98.Kf4 Rb5 99.Re6 Kg7 100.Kg4 Rb1 101.Ra6
According to Fundamental Chess Endings by K. Mueller and F Lamprecht they had this to say on the ending of R+4 pawns v R+3Pawns.
"This is one of the best known problems in endgame theory: is the attacker winning? Theoretically the answer is no, but in practice it is not at all easy to defend. First of all it must be stressed that just waiting passively is not sufficient."
"With the defender's h pawn on the fourth rank the attacker's success rate drops alot."